Air ionization equipment is used in a variety of industries for the elimination of unwanted and potentially harmful static electricity. Ionizers operated in conjunction with compressed air or gas are available as one option for static control. For example, an “in-line” ionizer is placed downstream of a compressed air source for delivering, through a tube or the like, ionization to a target. In-line ionizers are particularly useful in environments with limited space and proximity to sensitive equipment. In-line ionizers further provide the benefit of inserting ionization inside the production process, rather than simply in a production space.
In electronics and semiconductor manufacturing industries specifically, vulnerability to static voltages has increased as the size of electronics and semiconductor devices has shrunk. Thus, in-line ionization devices must continue to improve both the speed with which static is eliminated and the offset voltages produced by the ionizer itself. For example, some present in-line direct current (DC) ionizers can typically achieve worst-case balance offsets of ±50-60 volts (V). These ionizers conventionally include chambers made from plastic insulating material (e.g., polyethylene terephthalate (PET) or polytetrafluoroethylene (PTFE)) or anodized metal. The outlets typically consist of insulative material (e.g., PET, PTFE), anodized metal, or metal. Outlets constructed of insulative materials tend to charge due to the air flow, and cause imbalances. Outlets constructed of metal draw the ionization out of the air, reducing the amount of ionization available for neutralization, causing poor performance.
It is therefore desirable to provide an in-line gas ionizer with greatly reduced balance offset while maintaining good discharge speeds. The present invention fulfills this need.